In the field of data communications, communication equipment such as a modem, a data service unit (DSU), or a channel service unit (CSU) is used to convey information from one location to another. Digital technology now enables modems or other communication devices, such as frame relay data service units (DSU's), frame relay access units (FRAU's), and asynchronous transfer mode (ATM) communication devices to communicate large amounts of data in a packetized digital format. This packetized digital communication format generally adheres to a model, such as the well known Open Systems Interconnect (OSI) seven-layer model, which specifies the parameters and conditions under which information is formatted into a digital data packet and transferred over a communications network.
Frame relay networks, well known in the art, are one implementation of a packet-switching network. A packet-switching network allows multiple users to share data network facilities and bandwidth, as contrasted with a circuit-switching network which provides a specific amount of dedicated bandwidth to each user. Packet switches divide bandwidth into virtual circuits (VC). Virtual circuits, also known as circuit identifiers, can be a permanent virtual circuit (PVC) or a switched virtual circuit (SVC). As is well known, virtual circuit bandwidth is consumed only when data is actually transmitted. Otherwise, the bandwidth is not used. In this way, packet-switching networks essentially mirror the operation of a statistical multiplexer (whereby multiple logical users share a single network access circuit). Frame relay systems generally operate within layer 2 (the data link layer) of the OSI model, and are an improvement over previous packet switching techniques, such as X.25, in that a frame relay system requires significantly less control overhead.
FIG. 1 illustrates a communication environment 22 having an access provider network 24 and a network service provider (NSP) network 26. Typically, communication environment 22 would have a plurality of networks (not shown) interconnected together via communication links as described hereinafter. An example of a network is the public switched telephone network (PSTN) or a public data network (PDN). Access to the network is provided by an access provider. These access providers generally provide the communication and switching facilities over which the above-mentioned communication devices operate. Because of the evolution of the communication system from a plain old telephony system (POTS), originally designed to handle analog voice communications, to today's communication network capable of operating over a variety of physical connection systems using a variety of communication formats, the communication system employed today which provides both analog POTS voice capability and digital data capability is quite complex. Often, special interface devices are needed to provide connectivity between the different types of communication hardware and information formats. For example, a user of a digital data system for accessing the Internet may be employing an entirely different technology than the communication system employed by access provider network 24 which may be employing an ATM based communication network.
Typically, a user contracts with a network service provider (NSP) for network services. These networks typically sell network services, in the form of connectivity, to users. As illustrated in FIG. 1, the service provider's network 26 is shown to be separate from and adjacent to the access provider network 24. In instances where the user has contracted with the access provider for service, the access provider would also be the network service provider. On the other hand, the access provider and the NSP may be different entities. In this situation, the NSP may be far removed from the user, and connectivity between the user and the network service provider may be provided through one or more different access provider networks (not shown). Therefore, one skilled in the art will realize that FIG. 1 is provided as a simplified illustrative example of a portion of a communication environment 22.
A user may purchase a particular level of service from the NSP (not shown). This level of service can be measured by, for example, network availability as a percentage of total time on the network, the amount of data actually delivered through the network compared to the amount of data attempted or possibly the network latency, or the amount of time it takes for a particular communication to traverse the network. Often, an NSP may provide services to the user by specifying a committed information rate (CIR). The CIR is the minimum data communication rate that the NSP guarantees to the user. The CIR is typically some fraction of the total available line rate of the particular service being provisioned. For example, in a frame relay network, the line rate may be 1536000 bits/second (T1 rate including 24 64-kilobit (KB) channels for a total of 1.544 megabits/second (MB/s) including 8 KB signaling), while the CIR may be 48000 bytes/second (384000 bits/second (b/s)). That is, for this example, the NSP may guarantee a communication rate of 384000 b/s, while the total available line rate may be 1536000 b/s.
FIG. 1 shows a simplified illustrative communication environment 22 in which a plurality of user devices 28 and 30 reside. Each user device 28 and 30 is connected to a communication device 32 and 34, respectively, such as a frame relay or ATM access unit, via connections 36 and 38, respectively. User devices 28 and 30 are typically customer premises equipment, such as routers or the like, which may be connected to a local area network (LAN) or the like and residing off the access provider network 24. One skilled in the art will realize that the above-described communication devices and user devices may be of any of a wide variety of devices commonly employed in the industry.
For simplicity and as an example, only two communication devices 32 and 34, are depicted in FIG. 1. In practice, a communication environment 22 will contain many communication devices. Communication devices 32 and 34 are commonly considered communication endpoints and communicate with each other over an access provider network 24, in a conventional manner. The term communication device and endpoint are intended to be equivalent and are used interchangeably hereinafter. Access provider network 24 can be, for example, any network that provides connectivity for communication devices 32 and 34, and in the simplified illustrative example of FIG. 1, the portion of the access provider network shown is an ATM communication network. Access provider network 24 illustratively connects to communication devices 32 and 34 over connections 40 and 42, respectively. Connections 40 and 42 can be physical links and can be, for example but not limited to, T1/E1 service, digital subscriber line or loop (DSL), or any digital data service (DDS).
Access provider network 24 and NSP network 26 are typically characterized by a mesh network of links interconnecting a matrix of intermediate nodes (not shown) through switches, such as switches (S) 46, 48, 50, 52, 54 and 56, which are well known in the art. Communication links provide the physical connections between switches. For example, link 58 connects switches 46 and 48. Other links 60, some of which are shown as dotted lines for illustrative purposes, provide physical connections between other switches. For simplicity and as an example, only a limited number of switches and links are illustrated herein; however, access provider network 24 and NSP network 26 will typically contain many switching devices and links.
An operations center (OC) 62 is shown residing in access provider network 24. Within the OC 62 resides some of the control facilities necessary to maintain and operate the access provider network 24. As an illustrative example, a computer terminal 64 is shown residing in the OC 62. Computer terminal 64 interfaces with access unit (AU) 68 via connection 70 to provide an access provider operator management access to the various components of the access provider network 24. For further illustrative purposes, access unit 68 in OC 62 is shown connected to switch 52 via link 72 and connected to switch 48 over link 74. Additional links 60 may be used to connect to other switches throughout the access provider network 24 as necessary for the maintenance and operation of the access provider network 24. One skilled in the art will appreciate that an OC 62 will likely contain many computer terminals, switches and links which are not shown in the simplified illustrative example of FIG. 1.
FIG. 1 also illustrates a simplified NSP network 26. This simplified NSP network 26 is shown to have one switch 76. Also shown residing in the simplified NSP network 26 is an operations center (OC) 78. Residing in OC 78 is computer terminal 80 which interfaces with access unit 82 via line 84. Access unit 82 is connected to switch 76 via link 86. Connectivity between NSP network 26 is provided by link 88, which connects switch 76 with switch 48. Similar to access provider network 24, NSP network will likely have many computer terminals, switches, access units and links (not shown).
As part of the contract between a user and the NSP (not shown), a service contract may provide for servicing of the user's communication devices or other communication facilities which provide connectivity for the user to the access provider network 24 and/or NSP network 26. If the contract provides for a fully managed service, the NSP operator, typically working at the NSP's OC 78, would access the communication device on a regular basis to ensure the proper functioning of the communication device. If the access provider and the network provider are the same entity, then the access provider operator can easily establish access to a communication device through access provider network 24. For example, if the owner of user device 28 has contracted with the access provider, then access provider operator working out of OC 62 may access communication device 32 from computer terminal 64 by establishing a VC path from switch 68 to switch 48 via link 74, from switch 48 to switch 46 via link 58, and from switch 46 to communication device 32 over link 40.
Individual links in a frame-relay network are typically defined by data link connection identifiers (DLCIs), which are commonly used to identify the logical connection over which data communications are transported. PVCs are virtual circuits employed in an asynchronous transfer mode (ATM) network and/or a frame relay system. The use of frame relay DLCIs allows multiple logical connections to be multiplexed over the same channel. Alternatively, in the case of an ATM network, virtual path identifiers/virtual channel identifiers (VPI/VCIs) are used to identify the logical connection over which the data is transported. Here, in this simplified illustrative example of establishing connectivity between OC 62 and communications device 32, a series of VPI/VCIs would define the path 90 between switch 68 and communication device 32. The VPI/VCIs are shown as dash, double-dotted lines between the switches and parallel to the links to which a virtual circuit has been assigned. The series of frame relay DLCIs and/or ATM VPI/VCIs form a single path referred to as a virtual circuit (VC). A virtual circuit may be a permanent virtual circuit (PVC) such that the circuit is permanently established, or the VC may be a switched virtual circuit (SVC) which may be established as needed. In this simplified illustrative example where the owner of user device 28 has contracted with the access provider for network service, access provider operator working in OC 62 can access communication device 32 over VC path 90 (as denoted by the series of VPI/VCIs and/or DLCIs) to provide for the contracted services. For example, the access provider operator may be interested in assessing the performance of communication device 32 to determine if there are any dropped frames, if there is any bursting above CIR by the customer, and/or if there are any linked management interface (LMI) problems at a switch.
Alternatively, the owner of user device 28 may have contracted with a network service provider who is not the access provider. As shown in the simplified communication environment 22 of FIG. 1, the contracted network services may have to be provided from NSP network 26 through access provider network 24. In this situation, an NSP operator working from OC 78 may have to access communication device 32. The NSP operator would first have to contact the access provider operator working in OC 62, via communications path 94, with a request to establish connectivity between switch 50 and communication device 28. Here, a communications path 94 is shown connecting OC 78 with OC 62. Communications path 94 could be a POTS telephone line, a microwave channel, a satellite link, a radio channel or other commonly employed communication means. Then, VC 92 is established from switch 82 residing in OC 78 to the communication device 32. In this illustrative example, the VC 92 would be established over links 86, 88, 58 and 40. VC 92 may be either a PVC or an SVC depending upon a variety of factors, such as the nature of the agreement between the NSP and the access provider.
This process of manually requesting and then establishing a VC 92 from the NSP 26 to communication device 32 through an access provider's network 24 creates several problems and inefficiencies. First, it takes time for NSP operator to contact the access provider operator to request the establishment of PVC 92. This time equates to personnel expenses and inefficient use of personnel time. Furthermore, either operator may be needlessly distracted from higher priority tasks when initiating or responding to requests to establish PVC 92.
Also, the access provider operator may need to verify that the request to establish PVC 92 is authorized. That is, it would be undesirable for the access provider to allow unauthorized access to communication device 32. Verification of the requesting parties' authority to access communication device 32 equates to an added cost and additional personnel time inefficiencies.
Additionally, manual establishment of VC 92 requires time and effort from the access provider operator, thereby resulting in another inefficient use of personnel time and money.
A related problem arises from the inefficient use of Internet Protocol (IP) addresses. When a large number of communication devices and their associated VCs are to be established and maintained on an on-going basis, a corresponding large number of IP addresses are utilized. Given that there are a limited number of IP addresses available, there is a need to provide the necessary access to communication devices without the associated inefficient use of IP addresses.
A related problem may be imposed upon the user. When the user is not able to communicate at CIR, the user may begin incurring costs associated with the degraded performance. The user will likely then contact the NSP operator to complain about the degraded service and request remedial actions to fix the problem. Because establishing VC 92 is a time consuming and labor intensive process, a substantial length of time may be required before the user's service level is re-established up to the CIR. Therefore, the user may incur costs associated with the degraded performance until the NSP (not shown) has accessed the communication device, diagnosed the problem, and completed remedial actions. Reducing the time period to implement remedial actions would benefit the user.
Therefore, it would be desirable to provide a quick, reliable, efficient, and inexpensive method to establish a VC between a network service provider and a customer.